1. Field of the Invention
The present invention relates to a method according to the preamble of claim 1 for improving the selectivity of a polymer-film gas sensor.
The invention also concerns a sensor structure.
The present invention is particularly suited for extracting the specific signal of a single gas component from a composite signal representing at least one other gas component interfering strongly with the applied gas measurement technique.
2. Description of Background Art
A polymer-film gas sensor is characterized by being sensitive to a plurality of different gas species. A typical approach to improve sensor selectivity has been sought from a combination of several gas sensors of different types and then interpreting the output signals of such a sensor combination by means of, e.g., a neural network. However, this kind of a measurement system becomes complicated and costly.
Also known in the art are arrangements in which the polymer-film sensors are heated in order to restore their original properties in a manner described in, e.g., FI Pat. Appl. 942,727. While this technique is capable of restoring the sensor performance, the basic selectivity of the gas sensor under a normal measurement situation cannot be improved.
It is an object of the present invention to overcome the drawbacks of the above-described prior-art technique and to provide an entirely novel method for improving the selectivity of a polymer-film gas sensor.